English
Composition of maps corresponds to composing their images: map(g ∘ f) N = map g (map f N).
Русский
СпCombine отображений соответствует образам: map(g ∘ f) N = map g (map f N).
LaTeX
$$$ \operatorname{map}(g \circ f) N = \operatorname{map} g (\operatorname{map} f N) $$$
Lean4
theorem map_comp {M'' : Type*} [AddCommGroup M''] [Module R M''] [LieRingModule L M''] {g : M' →ₗ⁅R,L⁆ M''} :
N.map (g.comp f) = (N.map f).map g :=
SetLike.coe_injective <| by simp only [← Set.image_comp, coe_map, LieModuleHom.coe_comp]